For testing build a safari extension, just run it in Xcode. It will auto build the app and load it into Safari.

For the first time: ref: https://instabug.com/blog/how-to-submit-app-to-app-store/ </br> Routine update: https://help.apple.com/xcode/mac/current/#/dev442d7f2ca

Change the version number and build number before upload it to app store